Anionic monoazo dyes

ABSTRACT

Anionic monoazo dyes of the formula (1) in which A represents 1- or 2-naphthyl residue, which is substituted by a total of one or two sulphonic and/or carboxylic acid groups. R 1  represents hydrogen or C 1 -C 4 alkyl, each D 1  and D 2 , independently of the other, represent either an amino acid residue resulting from removal of a hydrogen atom from the amino group of the amino acid or the residue —NR 2 R 3 , in which each R 2  and R 3 , independently of the other, represent hydrogen, C 1 -C 4 alkyl, C 2 -C 6 alkyl which is substituted by hydroxy, halogen or cyano, phenyl which is unsubstituted or monosubstituted by hydroxy, halogen, SO 3 H, C 1 -C 4 alkyl or C 1 -C 4 alkoxy or alternatively, R 2  and R 3 , together with the nitrogen atom to which they are connected, complete a saturated 5- or 6-membered ring which may contain, in addition to the nitrogen atom, one nitrogen or oxygen atom and which may be further substituted and n is 0 or 1, a process for their preparation and the use of these dyes for dyeing natural or synthetic materials, in particular, paper.

The present invention relates to novel anionic monoazo dyes, a processfor their preparation and the use of these dyes for dyeing natural orsynthetic materials, in particular, paper.

Monoazo dyes based on coupling reactions of diazotised aromatic amineswith 1,3,5-triazinyl-l-acid derivatives have previously been described,for example, in EP 548,795, solely in the form of reactive dyes forcotton.

Furthermore, in recent years, the use of concentrated aqueous solutionsof dyes has gained importance because of the advantages possessed bysuch solutions when compared with dyes in powder form. The use ofsolutions avoids the difficulties associated with dust formation andreleases the user from the time-consuming and frequently difficultdissolving of the dye powder in water. The use of concentrated solutionswas also prompted by the development of continuous dyeing processes forpaper, since it is convenient In these processes to meter the solutiondirectly into the pulp stream or to add it at some other suitable pointof the papermaking process.

Surprisingly, it has now been found that anionic dyes based on thischromophoric system are especially valuable for use in dyeing paper,since they possess highly desirable yellowish-red shades. Such shades ofdyeings have, hitherto, only been attainable with difficulty, since nosingle dyestuff has been available and it has been necessary toincorporate mixtures of yellow and red dyes to obtain such shades.Furthermore, the dyes of the present invention exhibit high degrees ofexhaustion under particular dyeing conditions, resulting in dyeings ofexceptional brilliance not obtainable by the use of mixtures. Inaddition the dyes of the invention exhibit excellent water-solubility,thus enabling the ready preparation of concentrated liquid sellinggrades.

Accordingly, the invention relates to compounds of the formula

in which

-   -   A represents a 1- or 2-naphthyl residue, which is substituted by        a total of one or two sulphonic and/or carboxylic acid groups,        preferably a 1- or 2-naphthyl mono- or disulphonic acid or a 1-        or 2-naphthyl monocarboxylic acid residue,    -   R₁ represents hydrogen or C₁-C₄alkyl, each    -   D₁ and D₂, independently of the other, represent either        -   an amino acid residue resulting from removal of a hydrogen            atom from the amino group of the amino acid or the residue    -   —NR₂R₃, in which each    -   R₂ and R₃, independently of the other, represent hydrogen,        C₁-C₄alkyl, C₂-C₆alkyl which is substituted by hydroxy, halogen        or cyano, phenyl which is unsubstituted or monosubstituted by        hydroxy, halogen, SO₃H, C₁-C₄alkyl or C₁-C₄alkoxy or,        alternatively,    -   R₂ and R₃, together with the nitrogen atom to which they are        connected, complete a saturated, 5- or 6-membered ring which may        contain, in addition to the nitrogen atom, one nitrogen or        oxygen atom and which may be further substituted and    -   n is 0 or 1.

More preferred compounds of formula (1) are those in which

-   -   R₁ represents hydrogen    -   D₁ and D₂, independently of the other, is an amino acid residue        resulting from removal of a hydrogen atom from the amino group        of the amino acid and which is derived from glycine, alanine,        serine, cysteine, phenylalanine, tyrosine        (4-hydroxyphenylalanine), diiodotyrosine, tryptophan        (β-indolylalanine), histidine ((β-imidazolylalanine),        α-aminobutyric acid, methionine, valine (α-aminoisovaleric        acid), norvaline, leucine (α-aminosocaproic acid), isoleucine        (α-amino-β-methylvaleric acid), norleucine (α-amino-n-caproic        acid), arginine, ornithine (α,δ-diaminovaleric acid), lysine        (α,ε-diaminocaproic acid), aspartic acid (aminosuccinic acid),        glutamic acid (α-aminoglutaric acid), threonine and        hydroxyglutamic acid as well as mixtures and optical isomers        thereof or from iminodiacetic acid, a residue    -   —NR₂R₃, in which each    -   R₂ and R₃, independently of the other, represent hydrogen,        C₂-C₄hydroxyalkyl, phenyl, which is unsubstituted or        monosubstituted by SO₃H or, alternatively, a morpholino,        piperidino or pyrrolidino residue.

Especially preferred compounds of formula (1) are those in which

-   -   A represents a 1-naphthyl-2-, 3-, 4-, 5-, 6-, 7- or 8-sulphonic        acid, a 2-naphthyl-1-, 5-, 6- or 7-sulphonic acid, a        2-naphthyl-1-, 3- or 6-carboxylic acid, a 1-naphthyl-3,8- or        4,8-disulphonic acid or a 2-naphthyl-1,5-, 3,6-, 4,8- or        6,8-disulphonic acid residue and each    -   D₁ and D₂, independently of the other, is an amino acid residue        from which a hydrogen atom on the amino group has been removed        and which is derived from glycine, alanine, serine,        phenylalanine, aspartic acid (aminosuccinic acid) or glutamic        acid (α-aminoglutaric acid), a residue    -   —NR₂R₃, in which each    -   R₂ and R₃, independently of the other, represent hydrogen,        C₂-C₃hydroxyalkyl, phenyl, which is unsubstituted or        monosubstituted by SO₃H or, alternatively, a morpholino residue.

Most especially preferred compounds of formula (1) are those in which

-   -   A represents a 1-naphthyl-2-, 3-, 4-, 5-, 6-, 7- or 8-sulphonic        acid, a 2-naphthyl-1-, 5-, 6- or 7-sulphonic acid, a        2-naphthyl-1-, 3- or 6-carboxylic acid, a 1-naphthyl-3,8- or        4,8-disulphonic acid or a 2-naphthyl-1,5-, 3,6-, 4,8- or        6,8-disulphonic acid residue, most especially, when    -   n is 0, a 2-naphthyl-6- or 7-sulphonic acid residue and, when    -   n is 1, a 1-naphthyl-4-sulphonic acid, 2-naphthyl-6-sulphonic        acid or a 2-naphthyl-1,5-disulphonic acid residue,    -   R₁ represents hydrogen and both    -   D₁ and D₂ represent the group —NHCH₂CH₂OH.

The sulphonic and/or carboxylic acid groups present in compounds offormula (1) may be present either in the form of the free acid or in thesalt form, SO₃M and/or CO₂M. M is preferably one equivalent of acolourless cation, typically lithium, sodium, potassium, ammonium or theprotonated form of a C₄-C₁₂trialkylamine, C₄-C₁₂diamine,C₂-C₁₂-alkanolamine or of a polyglycol amine, conveniently,triethanolamine trisglycol ether, or mixtures of such cationic species.

M as a protonated C₄-C₁₂trialkylamine may, for example, be a protonatedN-ethyl-dimethylamine, N,N-diethylmethylamine, tri-n-propylamine,tri-n-butylamine, tri-isobutylamine, and, preferably, triethylamine ortriisopropylamine.

M as a protonated C₄-C₁₂diamine may, for example, be ethylenediamine, or1,3-diaminopropane, in which one or both nitrogen atoms are additionallysubstituted by one or two C₁-C₄alkyl radicals, preferably methyl orethyl radicals. M is preferably an N,N-dialkylethylenediamine orN,N-dialkyl-1,3-diaminopropane. Illustrative examples are:N-ethylethylenediamine, N,N-dimethylethylenediamine,N,N′-dimethylethylenediamine, N,N-diethylethylenediamine,3-dimethylamino-1-propylamine or 3-diethylamino-1-propylamine. M as aprotonated C₂-C₁₂alkanolamine may be the protonated form of amonoalkanolamine, dialkanolamine, monoalkanolmonoalkylamine,monoalkanoldialkylamine, dialkanolalkylamine or trialkanolamine or amixture of different protonated alkanolamines. Illustrative examplesare: protonated 2-aminoethanol, bis(2-hydroxyethyl)amine,N-(2-hydroxyethyl)dimethylamine, N-(2-hydroxyethyl)diethylamine,N,N-bis(2-hydroxyethyl)ethylamine or tris(2-hydroxyethyl)-amine.

Within the scope of the definitions of R₁ as C₁-C₄alkyl and R₂ and/or R₃as C₁-C₄alkyl and/or C₂-C₆alkyl which is substituted by hydroxy, halogenor cyano, these alkyl radicals may be branched or unbranched, forexample, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl,isobutyl, t-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl,1,3-dimethylbutyl or n-hexyl.

Similarly, C₁-C₄alkoxy may be, for example, methoxy, ethoxy, n-propoxy,isopropoxy, n-butoxy, sec-butoxy, isobutoxy or t-butoxy.

Halogen in the above formulae and radicals is iodine, bromine, fluorineor, especially, chlorine.

The dyes of formula (1) of the invention may be prepared by knownmethods, for example by reacting the diazonium salt of an amine of theformulaA-NH₂   (2)with either 2-amino- or2-C₁-C₄alkylamino-5-hydroxynaphthalene-7-sulphonic acid (where n=0) orwith 2-(4amino- or 4-C₁-C₄alkylaminobenzoyl)amino- orC₁-C₄alkylamino-5-hydroxynaphthalene-7-sulphonic acid (where n=1),reaction with cyanuric chloride and subsequent sequential reaction ofthe dichloro intermediate with amines D₁H and D₂H or, alternatively,reacting 2-amino- or 2-C₁-C₄ alkylamino-5-hydroxynaphthalene-7-sulphonicacid (where n=0) or 2-(4-amino- or 4-C₁-C₄alkylaminobenzoyl)amino- orC₁-C₄alkylamino-5-hydroxynaphalene-7-sulphonic acid (where n=1) withcyanuric chloride, followed by sequential reaction of the dichlorointermediate with amines D₁H and D₂H and, finally, reaction with thediazonium salt of the amine of formula (2), whereby A, D₁, D₂ and n areas previously defined, the latter procedure being preferred.

The dyes of the invention may be used to dye natural or syntheticmaterials, for example, cellulosic materials, carbonamide groupcontaining materials such as polyamides, leather or glass fibres, butare particularly useful for dyeing paper. They are preferably used as asolid or liquid commercial form.

The pulverulent or granular form of the dye can be used particularly inbatchwise pulp dyeing where the dye mixture, customarily in the form ofa stock solution, is added in the pulper, in the beater or in the mixingchest. Preference is here given to using dye preparations which as wellas the dye, may further include extenders, for example urea assolubilizer, dextrin, Glauber salt, sodium chloride and alsodispersants, dustproofing agents and sequestrants, such as tetrasodiumphosphate.

The present invention accordingly further provides solid dyepreparations for dyeing paper comprising a compound of the formula (1)and, optionally, further auxiliaries.

The present invention further provides aqueous solutions, preferablyconcentrated solutions, for dyeing paper, comprising a compound of theformula (1), preferably in a concentration of from 5 to 30% by weight.Due to their excellent solubility in water, the dyes of formula (1) areparticularly suitable for the preparation of such solutions.

The concentrated solutions preferably contain a low level of inorganicsalts, which may be achieved, if necessary, by known methods, forexample reverse osmosis.

The solutions may include further auxiliaries, for example solubilizerssuch as ε-caprolactam or urea, organic solvents, for example glycols,polyethylene glycols, dimethyl sulphoxide, N-methylpyrrolidone,acetamide, alkanolamines or polyglycolamines, which is a still furtheraspect of the invention.

In addition, the aqueous dye solutions of the present invention may beapplied to paper by use of the so-called spraying technique.

The novel dyes of the invention dye paper in predominantly reddishshades with excellent degrees of exhaustion with high colour strength,whilst being sufficiently water-soluble to provide stable aqueousformulations without the need for large quantities of solubilizers.Furthermore, dyeings obtained exhibit high degrees of bleed- andlight-fastness and are readily bleachable.

Furthermore, as a result of their high colour strength and watersolubility, the novel dyes of the invention are suitable for use in theink-jet printing method.

Consequently, one further aspect of the invention is paper, which isdyed with a compound of the formula (1), either in the form of a soliddye preparation, or an aqueous solution, as described above, as well asthe use of the compounds of formula (1), according to the invention, fordyeing paper.

The following examples serve to illustrate the invention withoutintending to be restrictive in nature. Parts and percentages are byweight unless otherwise stated.

EXAMPLES

(A) Synthesis of Intermediate Triazinylamino-l-acid Derivatives

Example 1

36.9 g of cyanuric chloride are dissolved in 185ml of acetone and addedto 200 g of ice water at 0° C. At an initial temperature of 0-50° C.and, subsequently, at 20° C., 28.7 g of ethanolamine are added drop wisewith stirring, the pH being maintained at 5.5-6.5. After 2.5 hours, thetemperature is increased to 40-50° C. and the pH maintained at 6.5-7.0by addition of a total of 164 ml of 2N aqueous sodium hydroxidesolution. After a further 2 hours the consumption of sodium hydroxideceases, the reaction mixture is stirred for a further 30 minutes, cooledto room temperature and the white suspension filtered. There areobtained 46.7 g of the disubstituted intermediate which are suspended in300 g of water and treated with 47.9 g of l-acid (7-amino-4-hydroxynaphthalene-2-sulphonic acid). The resulting beige suspension is heatedto 85° C. and the pH maintained at 3.0 by addition of a total of 94 mlof 2N aqueous sodium hydroxide solution. After stirring for 3 hoursreaction is complete, the pH is adjusted to 5.5 by addition of a further8 ml of 2N aqueous sodium hydroxide solution, the suspension cooled toroom temperature and the precipitated solids filtered. There areobtained 77 g of the compound of formula (100a).

Example 2

36.9 g of cyanuric chloride are dissolved in 185 ml of acetone and addedto 200 g of ice water at 0° C. At an initial temperature of 0-5° C. and,subsequently, at 20° C., 28.7 g of ethanolamine are added drop wise withstirring, the pH being maintained at 5.5-6.5. After 2.5 hours, thetemperature is increased to 40-50° C. and the pH maintained at 6.5-7.0by addition of a total of 164 ml of 2N aqueous sodium hydroxidesolution. After a further 2 hours the consumption of sodium hydroxideceases, the reaction mixture is stirred for a further 30 minutes, cooledto room temperature and the white suspension filtered. There areobtained 46.7 g of the disubstituted intermediate which are suspended in300 g of water and treated with 71.7 g of p-aminobenzoyl-l-acid(7-(4-benzoylamino)-4-hydroxy naphthalene-2-sulphonic acid). Theresulting beige suspension is heated to 100° C. and the pH maintained at3.0 by addition of a total of 86 ml of 2N aqueous sodium hydroxidesolution. After stirring for 6 hours reaction is complete, the pH isadjusted to 5.7 by addition of a further 16 ml of 2N aqueous sodiumhydroxide solution, the suspension cooled to room temperature and theprecipitated solids filtered. After purification by washing with dilutehydrochloric acid, there are obtained 80 g of the compound of formula(100b).

Examples 3-150

By proceeding in an analogous manner to that described in Examples 1 or2, respectively, but replacing the ethanolamine by amines D₁H and/orD₂H, the following compounds of formula

are obtained, as summarized in Table 1 below. TABLE 1 Example NrCompound Nr D₁ D₂ n 3 (101a) —NHCH₂CH₂OH —N(CH₂CH₂OH)₂ 0 4 (101b)—NHCH₂CH₂OH —N(CH₂CH₂OH)₂ 1 5 (102a) —NHCH₂CH₂OH —NHCH₂CH(CH)₃OH 0 6(102b) —NHCH₂CH₂OH —NHCH₂CH(CH)₃OH 1 7 (103a) —NHCH₂CH₂OH

0 8 (103b) —NHCH₂CH₂OH

1 9 (104a) —NHCH₂CH₂OH

0 10 (104b) —NHCH₂CH₂OH

1 11 (105a) —NHCH₂CH₂OH

0 12 (105b) —NHCH₂CH₂OH

1 13 (106a) —NHCH₂CH₂OH

0 14 (106b) —NHCH₂CH₂OH

1 15 (107a) —N(CH₂CH₂OH)₂ —N(CH₂CH₂OH)₂ 0 16 (107b) —N(CH₂CH₂OH)₂—N(CH₂CH₂OH)₂ 1 17 (108a) —N(CH₂CH₂OH)₂ —NHCH₂CH(CH)₃OH 0 18 (108b)—N(CH₂CH₂OH)₂ —NHCH₂CH(CH)₃OH 1 19 (109a) —N(CH₂CH₂OH)₂

0 20 (109b) —N(CH₂CH₂OH)₂

1 21 (110a) —N(CH₂CH₂OH)₂

0 22 (110b) —N(CH₂CH₂OH)₂

1 23 (111a) —N(CH₂CH₂OH)₂

0 24 (111b) —N(CH₂CH₂OH)₂

1 25 (112a) —N(CH₂CH₂OH)₂

0 26 (112b) —N(CH₂CH₂OH)₂

1 27 (113a) —NHCH₂CH(CH)₃OH —NHCH₂CH(CH)₃OH 0 28 (113b) —NHCH₂CH(CH)₃OH—NHCH₂CH(CH)₃OH 1 29 (114a) —NHCH₂CH(CH)₃OH

0 30 (114b) —NHCH₂CH(CH)₃OH

1 31 (115a) —NHCH₂CH(CH)₃OH

0 32 (115b) —NHCH₂CH(CH)₃OH

1 33 (116a) —NHCH₂CH(CH)₃OH

0 34 (116b) —NHCH₂CH(CH)₃OH

1 35 (117a) —NHCH₂CH(CH)₃OH

0 36 (117b) —NHCH₂CH(CH)₃OH

1 37 (118a)

0 38 (118b)

1 39 (119a)

0 40 (119b)

1 41 (120a)

0 42 (120b)

1 43 (121a)

0 44 (121b)

1 45 (122a)

46 (122b)

1 47 (123a)

0 48 (123b)

1 49 (124a)

0 50 (124b)

1 51 (125a)

0 52 (125b)

1 53 (126a)

0 54 (126b)

1 55 (127a) —NHCH₂CH₂OH

0 56 (127b) —NHCH₂CH₂OH

1 57 (128a) —N(CH₂CH₂OH₎₂

0 58 (128b) —N(CH₂CH₂OH)₂

1 59 (129a) —NHCH₂CH(CH)₃OH

0 60 (129b) —NHCH₂CH(CH)₃OH

1 61 (130a)

0 62 (130b)

1 63 (131a)

0 64 (131b)

1 65 (132a)

0 66 (132b)

1 67 (133a)

0 68 (133b)

1 69 (134a)

0 70 (134b)

1 71 (135a) —NHCH₂CH₂OH

0 72 (135b) —NHCH₂CH₂OH

1 73 (136a) —N(CH₂CH₂OH)₂

0 74 (136b) —N(CH₂CH₂OH)₂

1 75 (137a) —NHCH₂CH(CH)₃OH

0 76 (137b) —NHCH₂CH(CH)₃OH

1 77 (138a)

0 78 (138b)

1 79 (139a)

0 80 (139b)

1 81 (140a)

0 82 (140b)

1 83 (141a)

0 84 (141b)

1 85 (142a)

0 86 (142b)

1 87 (143a) —NHCH₂CH₂OH

0 88 (143b) —NHCH₂CH₂OH

1 89 (144a) —N(CH₂CH₂OH)₂

0 90 (144b) —N(CH₂CH₂OH)₂

1 91 (145a) —NHCH₂CH(CH)₃OH

0 92 (145b) —NHCH₂CH(CH)₃OH

1 93 (146a)

0 94 (146b)

0 95 (147a)

0 96 (147b)

1 97 (148a)

0 98 (148b)

1 99 (149a)

0 100 (149b)

1 101 (150a)

0 102 (150b)

1 103 (151a) —NHCH₂CH₂OH

0 104 (151b) —NHCH₂CH₂OH

1 105 (152a) —N(CH₂CH₂OH)₂

0 106 (152b) —N(CH₂CH₂OH)₂

1 107 (153a) —NHCH₂CH(CH)₃OH

0 108 (153b) —NHCH₂CH(CH)₃OH

1 109 (154a)

0 110 (154b)

1 111 (155a)

0 112 (155b)

1 113 (156a)

0 114 (156b)

1 115 (157a)

0 116 (157b)

1 117 (158a)

0 118 (158b)

1 119 (159a) —NHCH₂CH₂OH

0 120 (159b) —NHCH₂CH₂OH

1 121 (160a) —N(CH₂CH₂OH)₂

0 122 (160b) —N(CH₂CH₂OH)₂

1 123 (161a) —NHCH₂CH(CH)₃OH

0 124 (161b) —NHCH₂CH(CH)₃OH

1 125 (162a)

0 126 (162b)

1 127 (163a)

0 128 (163b)

1 129 (164a)

0 130 (164b)

1 131 (165a)

0 132 (165b)

1 133 (166a)

0 134 (166b)

1 135 (167a) —NHCH₂CH₂OH

0 136 (167b) —NHCH₂CH₂OH

1 137 (168a) —N(CH₂CH₂OH)₂

0 138 (168b) —N(CH₂CH₂OH)₂

1 139 (169a) —NHCH₂CH(CH)₃OH

0 140 (169b) —NHCH₂CH(CH)₃OH

1 141 (170a)

0 142 (170b)

1 143 (171a)

0 144 (171b)

1 145 (172a)

0 146 (172b)

1 147 (173a)

0 148 (173b)

1 149 (174a)

0 150 (174b)

1(B) Synthesis of Dyes

Example 151

4.5 g of 2-naphthylamine-6-sulphonic acid are suspended in 150 g ofwater and 5.7 g of concentrated hydrochloric acid and the suspensiontreated with a total of 5 ml of 4N aqueous sodium nitrite solution over30 minutes at 0-5° C. The mixture is then stirred for a further 30minutes and excess nitrite destroyed by addition of 3 ml of 2N aqueoussulphamic acid solution. The resulting orange suspension is then addedover 30 minutes at 100° C. to a suspension of 11.3 g of compound (100a)in 100 g of water, the pH of which had previously been adjusted to 5.0by addition of a small amount of 2N aqueous sodium hydroxide solution.During the addition, the pH is maintained at 5.0-5.5 by addition of atotal of 27.9 ml of 4N aqueous sodium hydroxide solution. After stirringfor a further 1.5 hours at room temperature, the pH is adjusted to 8-9to dissolve excess of the coupling component and the solution salted outby addition of 80 g of sodium chloride. After stirring for a further 45minutes, the resulting red suspension is filtered and the solids washedwith a small quantity of water. After drying, there are obtained 8.2 gof the compound of formula (175).

Example 152

11.2 g of 2-naphthylamine-7-sulphonic acid are suspended in 250 g ofwater and 14.2 g of concentrated hydrochloric acid and the suspensiontreated with a total of 12.5 ml of 4N aqueous sodium nitrite solutionover 30 minutes at 0-5° C. The mixture is then stirred for a further 30minutes and excess nitrite destroyed by addition of 1 ml of 2N aqueoussulphamic acid solution. The resulting orange suspension is then addedover 1 hour at 10° C. to a suspension of 22.3 g of compound (100a) in 50g of water, the pH of which had previously been adjusted to 5.5 byaddition of a small amount of 2N aqueous sodium hydroxide solution.During the addition, the pH is maintained at 5.0-5.5 by addition of atotal of 15.6 ml of 4N aqueous sodium hydroxide solution. After stirringfor a further 3 hours at room temperature, the pH is adjusted to 8-9 todissolve excess of the coupling component and the solution salted out byaddition of 150 g of sodium chloride. After stirring for a further 15minutes, the resulting red suspension is filtered and the solids washedwith a small quantity of water. After drying, there are obtained 30 g ofthe compound of formula (176).

Examples 153-170

By proceeding in a manner analogous to that described in Examples 151and 152, but replacing the 2-naphththylamine-6- or 7-sulphonic acid byan equivalent quantity of the appropriate amine, the following compoundsof formula (4) are obtained, as summarized in Table 2 below. TABLE 2 (4)

Example Nr Compound Nr A₁ 153 (177)

154 (178)

155 (179)

156 (180)

157 (181)

158 (182)

159 (183)

160 (184)

161 (185)

162 (186)

163 (187)

164 (188)

165 (189)

166 (190)

167 (191)

168 (192)

169 (193)

170 (194)

Example 171

2.3 g of 1-napthylamine-4-sulphonic acid are suspended in 100 g of waterand 2.9 g of concentrated hydrochloric acid and the suspension treatedwith a total of 2.5 ml of 4N aqueous sodium nitrite solution over 30minutes at 0-5° C. The mixture is then stirred for a further 30 minutesand excess nitrite destroyed by addition of a small quantity of 2Naqueous sulphamic acid solution. The resulting suspension is then addedover 35 minutes at 10° C. to a suspension of 6.7 g of compound (100b) in100 g of water, the pH of which had previously been adjusted to 6.0 byaddition of a small amount of 2N aqueous sodium hydroxide solution.During the addition, the pH is maintained at 6.0-6.5 by addition of atotal of 14.9 ml of 2N aqueous sodium hydroxide solution. After stirringfor a further 1 hour at room temperature, 80 ml of methanol and 45 g ofsodium chloride are added. Stirring is continued for a further 15minutes, the resulting red suspension is filtered and the solids washedwith a small quality of water. After drying, there are obtained 7.5 g ofthe compound of formula (195).

Example 172

4.95 g of 2-naphthylamine-6-sulphonic acid are suspended in 100 g ofwater and 5.7 g of concentrated hydrochloric acid and the suspensiontreated with a total of 5.1 ml of 4N aqueous sodium nitrite solutionover 30 minutes at 0-5° C. The mixture is then stirred for a further 30minutes and excess nitrite destroyed by addition of a small quantity of2N aqueous sulphamic acid solution. The resulting suspension is thenadded over 1 hour at 10° C. to a suspension of 13.3 g of compound (100b)in 100 g of water, the pH of which had previously been adjusted to 5.5by addition of a small amount of 2N aqueous sodium hydroxide solution.During the addition, the pH is maintained at 5.0-5.5 by addition of atotal of 13.2 ml of 4N aqueous sodium hydroxide solution. After stirringfor a further 4 hours at room temperature, 250 ml of methanol and 35 gof sodium chloride are added. Stirring is continued for a further 30minutes, the resulting red suspension is filtered and the solids washedwith a small quantity of water. After drying, there are obtained 11.0 gof the compound of formula (196).

Example 173

3.7g of 2-naphthylamine-1,5-disulphonic acid are suspended in 50 g ofwater and 2.85 g of concentrated hydrochloric acid and the suspensiontreated with a total of 2.5 ml of 4N aqueous sodium nitrite solutionover 30 minutes at 0-5° C. The mixture is then stirred for a further 1hour and excess nitrite destroyed by addition of a small quantity of 2Naqueous sulphamic acid solution. The resulting suspension is then addedover 40 minutes at 10° C. to a suspension of 6.7 g of compound (100b) in10 g of water, the pH of which had previously been adjusted to 5.0 byaddition of a small amount of 2N aqueous sodium hydroxide solution.During the addition, the pH is maintained at 5.0-6.0 by addition of atotal of 18.3 ml of 2N aqueous sodium hydroxide solution. After stirringfor a further 1 hour at room temperature, 150 ml of methanol and 50 g ofsodium chloride are added. Stirring is continued for a further 30minutes, the resulting orange suspension is filtered and the solidswashed with a small quantity of water. After drying, there are obtained8.2 g of the compound of formula (197).

Examples 174- 190

By proceeding in a manner analogous to that described in Examples171-173, but replacing the 1-naphthylamine-4-sulphonic acid,2-naphthylamine-6-sulphonic acid or the 2-naphthylamine-1,5-disulphonicacid by an equivalent quantity of the appropriate amine, the followingcompounds of formula (5) are obtained, as summarized in Table 3 below.TABLE 3 (5)

Example Nr Compound Nr A₁ 174 (198)

175 (199)

176 (200)

177 (201)

178 (202)

179 (203)

180 (204)

181 (205)

182 (206)

183 (207)

184 (208)

185 (209)

186 (210)

187 (211)

188 (212)

189 (213)

190 (214)

Furthermore, by proceeding in a manner analogous to that described forthe preparation of the above dyes but utilizing the intermediates(101a)-(174b) described in Table 1 together with the amines described inExamples 151-190, dyes of the corresponding formulae (4) and (5) mayalso be obtained.

(C) Application Examples Examples 191-195

A mixture of 50% long fibre spruce sulphite bleached and 50% short fibrebeech sulphite bleached fibres is suspended in deionised water, as a 2%suspension, and refined and beaten to 22° SR (Schopper Riegler). Afterdewatering by means of a centrifuge and testing for dry weight, theequivalent to 10 g of dry fibre are placed in a beaker and made up tothe volume of 500 ml with tap water. After stirring for 1 hour,sufficient of the appropriate compound to produce a dyeing of 0.2standard depth, based on the weight of dry fibre, as a 5 g/l aqueoussolution is added to the furnish suspension and stirring continued for afurther 15 minutes. The suspension is made up to 700 ml with water andfrom 300 ml of the resulting suspension a hand sheet is produced using aLhomargy sheet former. After drying on a cylinder at 90° C. for 12minutes, the CIELab coordinates and degrees of exhaustion of the dyes inthe dyeings obtained are measured. The backwater ratings of theeffluents are also assessed on a scale of from 1 (very highly coloured)to 5 (colourless backwater). The results are summarized in Table 4below. TABLE 4 Exam- Com- Concen- Back- CIELab ple pound tration Degreeof water Coordi- Nr. Nr. for 0.2 St. D. Exhaustion rating nates 191(175) 0.57% 87-89% 3 H* 21.4 C* 49.6 L* 62.7 *a 46.2 *b 18.1 192 (176)0.74% 94-96% 3-4 H* 27.9 C* 55.3 L* 65.4 *a 48.9 *b 25.9 193 (195) 0.82%86-88% 3 H* 6.8 C* 43.5 L* 57.7 *a 43.2 *b 5.2 194 (196) 0.54% 98-99%4-5 H* 23.5 C* 52.0 L* 64.3 *a 47.7 *b 20.8 195 (197)  1.1% 79-81    2H* 37.4 C* 56.5 L* 69.2 *a 44.8 *b 34.3

1. A compound of the formula

in which A represents a 1- or 2-naphthyl residue, which is substitutedby a total of one or two sulphonic and/or carboxylic acid groups, R₁represents hydrogen or C₁-C₄alkyl, each D₁ and D₂, independently of theother, represent either an amino acid residue resulting from removal ofa hydrogen atom from the amino group of the amino acid or the residue—NR₂R₃, in which each R₂ and R₃, independently of the other, representhydrogen, C₁-C₄alkyl, C₂-C₆alkyl which is substituted by hydroxy,halogen or cyano, phenyl which is unsubstituted or monosubstituted byhydroxy, halogen, SO₃H, C₁-C₄alkyl or C₁-C₄alkoxy or, alternatively, R₂and R₃, together with the nitrogen atom to which they are connected,complete a saturated, 5- or 6-membered ring which may contain, inaddition to the nitrogen atom, one nitrogen or oxygen atom and which maybe further substituted and n is 0 or
 1. 2. A compound of formula (1),according to claim 1, in which A represents a 1- or 2-naphthyl mono- ordisulphonic acid or a 1- or 2-naphthyl monocarboxylic acid residue.
 3. Acompound of formula (1), according to claim 1, in which R₁ representshydrogen D₁ and D₂, independently of the other, is an amino acid residueresulting from removal of a hydrogen atom from the amino group of theamino acid and which is derived from glycine, alanine, serine, cysteine,phenylalanine, tyrosine (4-hydroxyphenylalanine), diiodotyrosine,tryptophan (β-indolylalanine), histidine ((β-imidazolylalanine),α-aminobutyric acid, methionine, valine (α-aminoisovaleric acid),norvaline, leucine (α-aminoisocaproic acid), isoleucine(α-amino-β-methylvaleric acid), norleucine (α-amino-n-caproic acid),arginine, ornithine (α,δ-diaminovaleric acid), lysine(α,Ε-diaminocaproic acid), aspartic acid (aminosuccinic acid), glutamicacid (α-aminoglutaric acid), threonine and hydroxyglutamic acid as wellas mixtures and optical isomers thereof or from iminodiacetic acid, aresidue —NR₂R₃, in which each R₂ and R₃, independently of the other,represent hydrogen, C₂-C₄hydroxyalkyl, phenyl, which is unsubstituted ormonosubstituted by SO₃H or, alternatively, a morpholino, piperidino orpyrrolidino residue.
 4. A compound of formula (1), according to claim 1,in which A represents a 1-naphthyl-2-, 3-, 4-, 5-, 6-, 7- or 8-sulphonicacid, a 2-naphthyl-1-, 5-, 6- or 7-sulphonic acid, a 2-naphthyl-1-, 3-or 6-carboxylic acid, a 1-naphthyl-3,8- or 4,8-disulphonic acid or a2-naphthyl-1,5-, 3,6-, 4,8- or 6,8-disulphonic acid residue and each D₁and D₂, independently of the other, is an amino acid residue from whicha hydrogen atom on the amino group has been removed and which is derivedfrom glycine, alanine, serine, phenylalanine, aspartic acid(aminosuccinic acid) or glutamic acid (α-aminoglutaric acid), a residue—NR₂R₃, in which each R₂ and R₃, independently of the other, representhydrogen, C₂-C₃hydroxyalkyl, phenyl, which is unsubstituted, ormonosubstituted by SO₃H or, alternatively, a morpholino residue.
 5. Aprocess for the preparation of the compound of formula (1), according toclaim 1, comprising reacting the diazonium salt of an amine of theformulaA-NH₂   (2) with either 2-amino- or2-C₁-C₄alkylamino-5-hydroxynaphthalene-7-sulphonic acid (where n=0) orwith 2-(4-amino- or 4-C₁-C₄alkylaminobenzoyl)amino- orC₁-C₄alkylamino-5-hydroxynaphthalene-7-sulphonic acid (where n=1),reaction with cyanuric chloride and subsequent sequential reaction ofthe dichloro intermediate with amines D₁H and D₂H or, alternatively,reacting 2-amino- or 2-C₁-C₄alkylamino-5-hydroxynaphthalene-7-sulphonicacid (where n=0) or 2-(4-amino- or 4-C₁-C₄alkylaminobenzoyl)amino- orC₁-C₄alkylamino-5-hydroxynaphthalene-7-sulphonic acid (where n=1) withcyanuric chloride, followed by sequential reaction of the dichlorointermediate with amines D₁H and D₂H and, finally, reaction with thediazonium salt of the amine of formula (2), whereby A, D₁, D₂ and n areas defined in claim
 1. 6. A solid dye composition for dyeing paper,comprising a compound of the formula (1), according to claim 1, and,optionally, further auxiliaries.
 7. An aqueous solution for dyeingpaper, comprising a compound of the formula (1), according to claim 1,and, optionally, further auxiliaries.
 8. An aqueous solution accordingto claim 7 containing, as further auxiliaries, solubilizers and/ororganic solvents.
 9. A paper which is dyed with a compound of theformula (1), according to claim 1, wherein the compound of formula (1)is in the form of a solid dye composition or an aqueous solution,comprising a compound of the formula (1), according to claim 1, andoptionally, further auziliaries.
 10. A method for dyeing pulp comprisingadding the compound of formula (1), according to claim 1 to a pulper.11. A method for dyeing paper comprising applying the compound offormula (1), according to claim 1, to paper.
 12. A method according toclaim 11, wherein the formula (1) of claim 1 is sprayed on the paper.